1. Field of the Invention
The present invention relates to a method and apparatus for image processing. In particular, the present invention relates to a method and apparatus for image processing capable of preventing unauthorized reproduction of an image by determining levels of significance in confidentiality and illegitimacy pertinent to the image using a radio frequency tag.
2. Description of the Related Art
An image reading apparatus reads an original document, which is hereinafter referred to as an “object material”, and obtains image data of the object material. The thus obtained image data is used in a variety of different ways. For example, in a case of copiers, the image data is reproduced as an image on a recording medium such as a recording sheet. In a case of digital systems, the image data is transferred from a scanner to a host apparatus such as a personal computer and is printed on a recording medium with a color printer connected to the host apparatus. In a case of a facsimile machine, the image data is transmitted via a communication system or a network to a different facsimile machine located at a remote site so as to be output in a hard copy form at the different facsimile machine.
In a case where an object material to be read by the image reading apparatus is a copy-prohibited document such as a banknote or a valuable paper, the image data obtained therefrom may be misused as data to generate a forged copy. In particular, the image data obtained by reading banknotes or valuable papers may be printed on recording sheets to be used as forged banknotes and forged valuable papers. In a case where a passbook having a page with specific seal impression is read to obtain image data of the page, the image data of the specific seal impression may digitally be cut using an image processing application to print a forged seal impression in color onto a sheet for applying a deposit withdrawal so that the deposit may illegally be withdrawn from a bank account of the passbook.
To eliminate the above-described misuses, the image reading apparatus needs to prevent counterfeiting of the object material. For example, the image processing apparatus may leave an object material unread or delete the image data obtained when the object material is found out to be a copy-prohibited document such as a banknote or a valuable paper. In this case, the image reading apparatus needs to determine whether or not the object material set in the image reading apparatus is the document which is prohibited from being copied.
The copy-prohibited document may be recognized using a determination method based on image comparison in which the image data obtained through the image reading apparatus is compared with pattern data previously stored in the image reading apparatus.
Some background image reading apparatuses employ a technique which uses a determination method based on image comparison. The technique focuses on detection of a shadowing printed on a banknote, for example, so that the banknote can be recognized with a relatively small amount of pattern data.
However, the image reading apparatus generally handles many kinds of object materials including not only those without a shadowing but also those with a shadowing. In a case of handling the object materials without a shadowing, an amount of pattern data will be increased and therefore, the image reading apparatus needs to have a greater amount of memory to previously store the pattern data for image comparison with various object materials to allow or disallow its copying. Further, the image reading apparatus carrying out the determination method based on image comparison may impose excessive load on image comparison. In addition, the image reading apparatus may need to have high performance image processing circuits for carrying out the above-described determination method, which results in an increase in production costs.
Further, when the determination method based on image comparison alone is carried out, the image reading apparatus tends to misidentify a non-copy-prohibited document as a copy-prohibited document when the former is similar to the latter.
In addition, the determination method based on image comparison is not applicable to an object material including pattern data that is not previously stored in the memory of the image reading apparatus. For example, when a new banknote is published after a release of the image reading apparatus, the new banknote cannot be determined as “copy disallowed”.
Even though it is desirable to determine copy permission before reading the object material, the determination method based on image comparison recognizes its pattern data after reading the image data of the object material. In addition, anti-counterfeit countermeasures of the object material determined as “copy disallowed” have not substantially been made.